During transport, the surfaces and edges of glass and glass ceramic panels must be shielded against mutual contact and contact with hard objects, since scratches substantially diminish their resilience to shock and bending.
For example, glass ceramic panels typically sized from 20.times.40 cm to 50.times.100 cm are transported in reusable boxes containing app. 150 pieces each, with the panels standing upright. Mutual contact of the panels is thereby prevented in that air cushion foils--so-called "burled" foils--or cardboard strips are interposed. The air cushion foil covers the panel surface completely, while the cardboard strips only cover app. 10-20% of the surface.
In both cases, a relatively large amount of material which has to be disposed of is left after unpacking. Recycling of the air cushion foil is uneconomical, due to its high transport volume, the variety of its external forms and the low cost of the new product.
Detachable synthetic jambs present a further option, but they must be elaborately secured against displacement and are barely usable with panels with larger, extended radii.
However, due to their low volume and usability with all panels not having radii, synthetic jambs are reusable.
A transport rack for glass panels is known from the DE 41 29 058 C1, comprising a warp-resistant base, wherein horizontal mounting ledges for upright arrangement of the glass panels and clamping means acting upon the upper edges of the erect glass panels are provided, whereby rows of orthogonal support rods forming slide-in compartments for individual glass panels to be inserted from above are arranged on the base and a slider-shaped holding member is spring-fastened to each support rod in such manner that under initial stress it is also attachable to the upper edge of the glass panel inserted in the slide-in compartment associated with the respective support rod.
The manufacture of the transport rack according to DE 41 29 058 is costly, and the rack is relatively fragile due to its many moving parts.
During installation and assembly of the glass ceramic panels, e.g., in the frame of the cooking range, it is vital to ensure that the panel is deposited flexibly and free of tension. For this purpose, separators are glued into the frame prior to deposition of the panel.
These separators are foam material strips of 1 to 2 mm thickness having a surface dimension of app. 5.times.10 mm, which are adhesive on one or both sides and of sufficient temperature stability. Two or three separators are applied to each side of the frame, whereby attention must be given to complete and precise positioning of the separators, since contact between the panel and the frame can cause damage resulting in a reduction of the firmness of the panel. In addition, a permanent elastic connection between the glass ceramic panel and the enclosing frame is needed to achieve the following:
stress-free mounting of the cooking surface in the enclosing frame; PA1 sealing of the upper side of the cooking surface against seepage of liquid into the space underneath containing live electrical components; and PA1 compensation of the elongation differences resulting from the differential thermal expansion of the frame material and the cooking surface during use.
This is presently achieved by appropriate positioning of the panel in the frame and by filling the gap with silicon adhesive.
The invention proceeds from the problem of providing an economic solution for safe and waste-avoiding transport and easy assembly, which also meets further safety requirements by providing, e.g., an inspection window for visual displays and safe-use indicators, for example, of water tightness, as well as providing for easy cleaning of the glass or glass ceramic panels integrated in the cooking range.
The problem is solved according to the present invention in that the transport shield remains permanently connected to the panel after transport, i.e., during installation, assembly and use. The transport shield is thereby usefully constructed to act as a protector during assembly, a positioning aid, a separator, an elongation compensating medium and/or a sealing member.
In a further embodiment, the transport shield provides an inspection window having a smooth surface facing outwards, in particular in profiled panels, by means of filling the profile, e.g., with a transport material (DE 41 04 983 C1).
In a preferred embodiment, the transport shield is glued to the panel, whereby the transport shield consists of permanently elastic compounds containing silicon, in particular silicon rubber and/or silicon resins and/or age-hardening or thermoplastic synthetic resins.
To ensure easy application, organic materials, i.e., synthetic resins, are preferred. Age-hardening synthetic resins, which are applied in highly viscous state and which form smooth surfaces due to their surface tension, are particularly suitable. A large variety of such age-hardening synthetic resins is commercially available. Epoxy resins, silicon resins, furan resins, polyester resins, acrylic resins or polyurethane resins are particularly suitable. Thermoplastic resins which also possess good transparency, such as, e.g., polyvinyl chloride, polystyrene and polyester, in particular acrylic resins, and polycarbonates as well as polyvinyl acetates and acetals are also suitable. In softened state, these thermoplastic materials can be pressed onto the heated or unheated panel with suitable implements or, according to a preferred embodiment, applied to the panel by means of spraying.
The transport shield according to the invention is connected to the panel particularly in the panel portions not subject to heating during use, thus ensuring that the organic compounds used are never brought to the limit of their temperature stability.
According to the invention, the transport shield is applied to one side of the panel, the bottom side.
The transport shield is thereby preferably arranged in the rim or edge area of the panel and can thus form an elastic cushion around its circumference protecting the panel against damage.
Due to the good level formation of the panels, a very small thickness of the transport shield in the range of 0.2 to 4 mm, in particular 1 to 2 mm, is sufficient to prevent damage during transport. Since the transport shield "cushions" are firmly connected to the panel and panels forming one batch are of identical dimension, small cushions of app. 5.times.5 mm to 10.times.10 mm are sufficient for reliable prevent of panel damage. The transport shield according to the invention may also be detachably connected to the panel, which is particularly advantageous when the panel is disassembled from the cooker and the operating and auxiliary means are to be removed, e.g., to recycle the panels.
Furthermore, it is also conceivable to connect the transport shield "cushions" detachably to the panel, if they are, e.g., also to be applied to the upper surface of the panel.
The invention also concerns means resp. auxiliary means for installation, assembly and operation of a glass or glass ceramic panel to be integrated in a cooking range as a cooking surface and/or means for forming an inspection window in a profiled panel, if said means resp. auxiliary means are permanently joined to the panel as a transport shield prior to preparing the panel for transport.